Battery - IID Tool Strangeness ?

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txfromwi

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This is for the 2015 LR4, 41K miles.

I purchased this LR4 last October, 2022 and replaced the OEM ! battery last November with an H7.
I did a battery reset with the IID Tool at that time.

2 weeks later the Aux battery dies - I have not replaced it - at least yet... (due to the below I have ordered one - will be here in a couple of weeks)

It has driven precious few miles and has been started only a few times.

I am getting it ready for the summer when my daughter returns from University.

I am getting Low Battery - Start Engine.
Fine, no problem, it's been a while so the battery will likely be low.

In the last 2 days I have run it in excess of 90 minutes, at idle and at ~2K rpm.

Still getting Low Battery... Hmmm...

IID Tool Body Control Module Live Values
For ALL parameters related to the battery and the alternator I get N/A. (other values appear to be fine..)
I cannot even get the voltage in this section, but I do get the voltage showing on the dash and on the phone in the top left.
It even says Number of Battery resets N/A, when I know I reset it last fall.

I did the "are the connections to the battery terminals ok" test as per the manual, i.e. while running turn absolutely everything electrical on and measure voltage difference between the terminal to the connector. All voltage differences were Zero, as they should be.

So....
Your thoughts please....
Main battery
ECO battery
IID Tool

Diagnostic tips,
etc.
etc

Many Thanks!
 

Cthehentz

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You want to replace both batteries at the same time, the old battery will always drain the good battery until they both level out usually lower. The aux battery for start stop features also runs certain electronics or in conjunction with the main battery.
 

txfromwi

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Thanks, I understand your logic and that is why I have an ECO/AUX battery on order.
I will report back on whether or not that makes a difference.
It would be nice if this was the fix.

But there seems to be no definitive determination whether that is actually the way it works.

Personally, we ran the 2016 LR4 with a dead AUX battery in place for over a year with no issues whatsoever, and and so have many others as per other threads.

There are plenty of folks who agree with you about certain electronics being run by the AUX battery, but I cannot validate that in either personal experience or by reading the mechanics manual - but you never know where in the manual those little hints are hidden - not in the AUX battery section at least!

We shall see...

But in the mean time, how can I further diagnose and why is the IIDTool not reporting the data?

Or is this just another, MY Rover is different than YOUR Rover because as we all know, they are each individually built from whatever way lying about the assembly floor that day...
 

greiswig

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You want to replace both batteries at the same time, the old battery will always drain the good battery until they both level out usually lower. The aux battery for start stop features also runs certain electronics or in conjunction with the main battery.
That's true when the batteries are not isolated from one another, but that's not the case here. And I don't think it's true here as a result. The isolation means that even a completely dead aux battery will only remove the stop/start functionality, but you can still start the vehicle just fine.
 

txfromwi

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Probably resolved.

Battery was likely discharged from sitting a long time and I did not re-charge properly, running the vehicle less than about 2 hours. See below...


Although this is the 2015, I did find this in the manual for the 2013.

"Do not rely on the generator to restore a discharged battery. For a generator to recharge a battery, it would take
in excess of eight hours continuous driving with no additional loads placed on the battery.

Trickle charging (defined as voltages <16 volts) may be carried out with the battery connected. Make sure that
the battery terminals are fully tightened prior to trickle charging."

Still don't know why the IIDTool would not provide data...
 
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